Various types of level detection systems are known to control on/off pump cycles. These include mechanical as well as non-mechanical level sensors. Examples include various types of known float or diaphragm switches. Known mechanical sensors while useful suffer from wear and mechanical stresses.
Non-mechanical level sensors are known and are improvements over the mechanical units. However known non-mechanical units require routine maintenance as they are affected by their environment and can suffer from contaminant build-up, mold, dirt, corrosion was well as contaminating liquid or moisture.